G2 QTof LockSpray fluidics pump countdown is inaccurate - WKB3985

SYMPTOMS

When pumping with the LockSpray fluidics, the timer says, for example, 400 minutes, but it counts down to 300 minutes in only about five actual minutes

ENVIRONMENT

Xevo QTof

Xevo G2 QTof

Xevo G2-S

Xevo G2XS

Synapt G1

Synapt G2

Synapt G2-S

Synapt G2-Si

CAUSE

Air bubbles in the fluidics lines

FIX or WORKAROUND

Verify that the fluidics has enough wash solution and that the two orange lines that run out of the top of the fluidics valves and run above the mass spectrometer reach down into the wash solvent. The wash solvent should be some mix of acetonitrile and water or methanol and water. If a high desolvation temperature is used, the wash solution should have a higher aqueous percentage, such as 80%. If nanoflow is used, the wash solution should have a higher organic percentage, such as 70%.

Purge at least four times with the new wash solution.

Pump through the LockSpray fluidics to the LockSpray probe. For electrospray, it should take no more than a few minutes for the beam to show at 10 µL/min. For nanospray at 0.5 µL/min. it may take as long as 15-30 minutes, depending on the line used to connect to the LockSpray emitter. During this time, the syringe is compressing, so the countdown may not start. Once compression is reached, the countdown for the LockSpray fluidics reservoir should mimic real time and not count down too quickly or too slowly. If the countdown is still too quick, purge again a few more times and ensure that the orange wash lines reach down into the solvent.